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Full-Text Articles in Ecology and Evolutionary Biology

Effects Of Low-Cost, Low-Tech Tools For Riparian Restoration On Prairie Streams In Western South Dakota, James Andrew Joseph Bolyard Jan 2024

Effects Of Low-Cost, Low-Tech Tools For Riparian Restoration On Prairie Streams In Western South Dakota, James Andrew Joseph Bolyard

Electronic Theses and Dissertations

Despite making up less than two percent of the overall landscape in the arid and semi-arid western US, riparian areas are a crucial resource for agriculture, livestock, and wildlife. However, many have impaired function and reduced riparian cover. Low-Cost, Low-Tech Tools (LCLTT) are a subset of Process-Based Restoration (PBR) used for riparian restoration that were chosen for their cost-effectiveness and minimal technical requirements. LCLTT has been tested in mountainous areas of the western US but only recently implemented in the Northern Great Plains (NGP). Given their novelty as an approach toward restoration for the region, professional restoration and landowner communities …


Plant Available Water Drives Semi-Arid Forage Quality And Quantity In A Common Garden Greenhouse Experiment, Parker J. Witt Jan 2024

Plant Available Water Drives Semi-Arid Forage Quality And Quantity In A Common Garden Greenhouse Experiment, Parker J. Witt

Electronic Theses and Dissertations

Rangeland forage nutrition and biomass production are integral components of sustainable livestock grazing systems and are controlled by soil quality and precipitation. I examined the effects of precipitation on growth and nutrition of three forage species in four different soils that span the longitudinal moisture gradient in South Dakota. I grew little bluestem (Schizachyrum scoparium), western wheatgrass (Pascopyrum smithii), and smooth brome (Bromus inermis) in soils representing the eastern tallgrass/mid-grass prairie (Brookings, 700 mm avg. precipitation.), an eastern mid-grass prairie (Highmore, 550 mm avg. precipitation.), a western mid-grass prairie (Cottonwood, 450 mm avg. precipitation.), and a western mid-grass/short-grass prairie (Sturgis, …


Translocations Of North American Bison Across Large Climatic Gradients: Impacts On Thermoregulation, Body Size, And Helmintic Infection, Hayden Wolfe Jan 2024

Translocations Of North American Bison Across Large Climatic Gradients: Impacts On Thermoregulation, Body Size, And Helmintic Infection, Hayden Wolfe

Electronic Theses and Dissertations

Every year, one-eighth of all North American bison (Bison bison) are translocated, often across large climatic gradients. Over the last 16 years bison have been translocated from Wind Cave National Park in South Dakota to establish six herds across the United States central grasslands in Iowa, Missouri, Illinois, Indiana, and Kansas. Influence of climatic gradients on herd-level thermoregulation, body size, and helmintic infection were evaluated. Overall, 1174 thermal images and 1050 fecal samples were collected between 2021 and 2023. Physiological heat flux was used to measure thermoregulation, asymptotic body mass (ABM) was used for body size, and helminth genera abundance …


Improving Stream Connectivity In South Dakota, Colton Rainier Curtis Jan 2024

Improving Stream Connectivity In South Dakota, Colton Rainier Curtis

Electronic Theses and Dissertations

Stream connectivity is crucial for fish movement and genetic diversity in fragmented landscapes. Road-crossings often act as barriers, disrupting hydrology and isolating fish populations. The Southeast Aquatic Resources Partnership (SARP) has developed rapid road-crossing assessment protocols and tools to prioritize restoration projects. However, managers lack tools for planning, directing, and initiating roadcrossing assessments. Managers also require modeling approaches to effectively identify and monitor road-crossings across dynamic stream networks. Presented here is a case study offering a roadmap for effective implementation of collaborative road-crossing assessments and prioritization of remediation projects, alongside an exploration of predictive modeling approaches to identify problematic crossings …


The Spatial Ecology Of Plains Spotted Skunks In South Dakota: Insights From Species Distribution, Resource Selection, And Co-Occurrence Models, Kara M. White Jan 2024

The Spatial Ecology Of Plains Spotted Skunks In South Dakota: Insights From Species Distribution, Resource Selection, And Co-Occurrence Models, Kara M. White

Electronic Theses and Dissertations

The plains spotted skunk (Spilogale interrupta) is a data-deficient small carnivore native to the central plains of North America that has experienced significant population declines. My dissertation investigates the species’ distribution, habitat associations, and interspecific interactions in South Dakota, providing crucial information for conservation actions. In Chapter 1, I developed ensemble distribution models on a broad scale, incorporating species location data from 1985–2020, environmental factors, and six predictive modeling algorithms. I identified key predictors including mean temperature diurnal range and proportion of area as pasture, and estimated ~31,300 km2 of potential habitat, predominately in eastern South Dakota. In Chapter 2, …


Soil Responses To Eastern Redcedar (Juniperus Virginiana L.) Afforestation And Prescribed Fire In South-Central South Dakota, Robert Schaefer Jan 2024

Soil Responses To Eastern Redcedar (Juniperus Virginiana L.) Afforestation And Prescribed Fire In South-Central South Dakota, Robert Schaefer

Electronic Theses and Dissertations

Research was conducted in 2019 and 2020 on rangelands located in south-central South Dakota assessing a number of physical, chemical, and biological properties of mineral ustepts and ustents soils associated with eastern redcedar (ERC) (Juniperus virginiana) afforestation and prescribed fire. ERC afforestation appeared to be associated with significantly higher field-condition soil aggregate stability, cation exchange capacity (CEC), soil pH, and fungi:bacteria (F:B) as well as significantly lower soil moisture, nitrate-N, phosphorus, bacteria biomass, and Gram-positive:Gram-negative (GP:GN) bacteria compared to native grassland conditions, while other mineral soil properties appeared relatively unaffected. Compared to soil conditions under dense, living ERC canopies, prescribed …


Methods For Optimizing Detection And Evaluating Habitat Use Of North American River Otters In South Dakota, Jessica Speiser Jan 2024

Methods For Optimizing Detection And Evaluating Habitat Use Of North American River Otters In South Dakota, Jessica Speiser

Electronic Theses and Dissertations

North American river otters (Lontra canadensis) play a critical role as an apex predator in riverine ecosystems. A challenging species to survey using traditional methods, they remain understudied in non-forested regions, such as the Northern Great Plains, where habitat degradation and landscape fragmentation may reduce habitat quality and availability and disrupt landscape connectivity. This thesis aims to improve detectability and investigates the habitat use of river otters in South Dakota to better understand habitat needs of otters and improve their continued recovery and management. My first chapter provides a brief overview of river otters and their ecological roles in freshwater …


Comparative Functional And Genomic Analysis Of Protein Targets Of Sexual Selection In Primates, Brianna Ports Dec 2023

Comparative Functional And Genomic Analysis Of Protein Targets Of Sexual Selection In Primates, Brianna Ports

Electronic Theses and Dissertations

Sexual selection is driven by the differential reproductive success of individuals, which is influenced by competition for mates and mate choice. In primates, this selective pressure has been attributed to the development of distinct anatomical, physiological, and behavioral characteristics. By employing comparative functional and genomic methodologies, this study aimed to assess the repercussions of primate sexual selection. To better understand the mechanisms driving sexually selected traits, an unbiased genome-wide analysis was used to associate rates of protein evolution with relative testes size and sexual size dimorphism. While previous research focused on the rapid evolution of male reproductive proteins in response …


Interactive Effects Of Sublethal Concentrations Of Fracking Biocides And Abandoned Mine Drainage On Amphipod Behavior, Kelly Lenhart Dec 2023

Interactive Effects Of Sublethal Concentrations Of Fracking Biocides And Abandoned Mine Drainage On Amphipod Behavior, Kelly Lenhart

Electronic Theses and Dissertations

This thesis examined the sublethal effects of three pollutants, namely glutaraldehyde, 4,4-dimethyloxazolidine (DMO), and abandoned mine drainage (AMD), on amphipods. The primary objective was to investigate their combined effects on amphipods. The three pollutants, despite having the potential to combine in the environment, have not been studied to determine their potential for detrimental interactive effects which could result in unexpected environmental damage.

The research employed a series of experimental setups involving controlled exposure of amphipods to varying, putatively sublethal, concentrations of the chemicals of interest. Subsequently, effects were assessed via both behavioral and feeding assessments. To facilitate this analysis, novel …


Population Trends And Trophic Ecology Of The Invasive Peacock Eel (Macrognathus Siamensis) In The Florida Everglades, Grace Kahmann Dec 2023

Population Trends And Trophic Ecology Of The Invasive Peacock Eel (Macrognathus Siamensis) In The Florida Everglades, Grace Kahmann

Electronic Theses and Dissertations

Invasive species threaten the ecological integrity of ecosystems worldwide, including the Florida Coastal Everglades. This study investigated the ecological role of the peacock eel (Macrognathus siamensis) within this ecosystem, emphasizing its population trends and the environmental factors that affect its population performance, and the potential for interactions with native fish assemblages and coastal food webs. I used 19 years of electrofishing data to investigate the population trends of peacock eels at the marsh-mangrove ecotone of the Shark River Estuary, Everglades National Park (Florida, USA). I found that peacock eel populations have increased since their first detection in 2002, and their …


Effects Of A Protection Zone In A Reaction-Diffusion Model With Strong Allee Effect., Isaac Johnson Dec 2023

Effects Of A Protection Zone In A Reaction-Diffusion Model With Strong Allee Effect., Isaac Johnson

Electronic Theses and Dissertations

A protection zone model represents a patchy environment with positive growth over the protection zone and strong Allee effect growth outside the protection zone. Generally, these models are considered through the corresponding eigenvalue problem, but that has certain limitations. In this thesis, a general protection zone model is considered. This model makes no assumption on the direction of the traveling wave solution over the Strong Allee effect patch. We use phase portrait analysis of this protection zone model to draw conclusions about the existence of equilibrium solutions. We establish the existence of three types of equilibrium solutions and the necessary …


Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil Dec 2023

Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …


Tropical Understory And Canopy Twig Ants (Pseudomyrmex): Natural History, Sensory Homing, And Neuroecology., Daniella Prince Aug 2023

Tropical Understory And Canopy Twig Ants (Pseudomyrmex): Natural History, Sensory Homing, And Neuroecology., Daniella Prince

Electronic Theses and Dissertations

In this dissertation, I examined the behavior of foraging twig ants, explored the sensory profile of their homing behavior, and investigated the role of habitat use in shaping the sensory neurobiology of species within the genus Pseudomyrmex (Hymenoptera: Formicidae). In chapter one, I reviewed the ecology of Pseudomyrmex, and introduced the focal species, P. boopis, a neotropical understory-dwelling twig ant. In chapter two, I described the natural history of P. boopis on Barro Colorado Island, Panama—specifically, their nesting habits, activity rhythm, and foraging behavior on understory surfaces. Pseudomyrmex boopis colonies were diurnal and nested in dead twigs in …


New Species Of Dryolestoid From The Late Cretaceous Allen Formation And Implications For South American Faunal Diversity., Brigid Erin Connelly Aug 2023

New Species Of Dryolestoid From The Late Cretaceous Allen Formation And Implications For South American Faunal Diversity., Brigid Erin Connelly

Electronic Theses and Dissertations

Dryolestoids are extinct cladotherians mammals from the Jurassic and Cretaceous periods. I describe a collection of dryolestoid specimens from the Late Cretaceous localities of Cerro Tortuga (Allen Formation), Anfiteatro 1, and Shining (both La Colonia Formation) from Patagonia, Argentina. Using comparative morphology, I identify a new species of meridiolestidan dryolestoid based on eleven specimens across both formations. The new species’ recovery from La Colonia Formation represents the first dryolestoid connection between the two approximately contemporaneous formations. The species’ morphology may represent an ecological shift within Meridiolestida from insectivory to herbivory, showing a transition in characters between the plesiomorphic sharp-toothed meridiolestidans …


Co-Flowering Community Effects On The Relative Contribution Of Pollen Quantity And Quality Limitation To The Reproductive Success Of Four Clarkia Species, Emma Moore Aug 2023

Co-Flowering Community Effects On The Relative Contribution Of Pollen Quantity And Quality Limitation To The Reproductive Success Of Four Clarkia Species, Emma Moore

Electronic Theses and Dissertations

More than 60% of plant populations experience low pollen availability which limits seed production (pollen limitation). Pollen limitation occurs due to low quantity or quality of pollen delivered to stigmas. Despite its ubiquity in nature, to date we still have limited understanding of the drivers of pollen limitation in plant communities. Plants typically occur in diverse communities where pollinator sharing is common and can influence quality and quantity aspects of pollen limitation. Co-flowering species can attract larger numbers of pollinators or they can compete for pollinators affecting pollen loads on stigmas. Pollinator competition may also lead to higher rates of …


The Old Family Clock: Exploring High Variation Of Chronotype In The Common House Spider, Parasteatoda Tepidariorum, Caitlin Jones Aug 2023

The Old Family Clock: Exploring High Variation Of Chronotype In The Common House Spider, Parasteatoda Tepidariorum, Caitlin Jones

Electronic Theses and Dissertations

Circadian rhythms are often tightly confined around a mean of 24 hours with little variation in traditional model organisms in the absence of environmental time cues. Some spider species fall well outside this normal range with mean periods of 18 hours and variation around these means of 6 hours or more. This extreme variation in circadian rhythm is not well-understood and is the focus of the current study. Using Parasteatoda tepidariorum as a model organism, we investigated whether variation in eight circadian parameters could be explained by genetic variability, environmental conditions, or an endogenous feature of the circadian system of …


Impacts Of Urbanization On Pollination Success For Common Milkweed (Asclepias Syriaca), David Rockow Aug 2023

Impacts Of Urbanization On Pollination Success For Common Milkweed (Asclepias Syriaca), David Rockow

Electronic Theses and Dissertations

Urbanization is among the greatest threats to biodiversity on the planet, and is projected to increase in magnitude in coming years. This growing threat makes it important to better understand how urbanization may impact vital ecosystem services, such as pollination. Studies on the impact of urbanization on pollination vary wildly in their findings. This study analyzed multiple aspects of pollination success in common milkweed populations varying in urbanization level, including insect community composition, pollen removal/deposition, and fruit/seed production. By analyzing multiple pollination aspects we can determine the overall mechanism in which urbanization instills on the entire pollination process. Overall, urbanization …


An Early Pliocene Fish Assemblage From The Southern Appalachians: Ichthyofauna Of The Gray Fossil Site, Shay Maden Aug 2023

An Early Pliocene Fish Assemblage From The Southern Appalachians: Ichthyofauna Of The Gray Fossil Site, Shay Maden

Electronic Theses and Dissertations

The Gray Fossil Site (GFS) preserves an early Pliocene sinkhole pond that accumulated a rich flora and vertebrate fauna. Fossils of fish are incredibly common at GFS, representing thousands of specimens recovered to date. Comparison with extant species reveals a depauperate freshwater fish fauna consisting of only two species: Lepomis sp. and Micropterus sp. The absence of fishes that are ubiquitous in modern streams suggests no perennial surface hydrologic connection between the Gray Fossil Site and the nearby Holston River. Limited opportunities for dispersal into the pond and deleterious conditions such as eutrophy and high competition may have resulted in …


Geometric Morphometric Analysis Of Modern Viperid Vertebrae Facilitates Identification Of Fossil Specimens, Lance D. Jessee Aug 2023

Geometric Morphometric Analysis Of Modern Viperid Vertebrae Facilitates Identification Of Fossil Specimens, Lance D. Jessee

Electronic Theses and Dissertations

Snake vertebrae are common in the fossil record, whereas cranial remains are generally fragile and rare. Consequently, vertebrae are the most commonly studied fossil element of snakes. However, identification of snake vertebrae can be problematic due to extensive variation. This study utilizes 2-D geometric morphometrics and canonical variates analysis to 1) reveal variation between genera and species and 2) classify vertebrae of modern and fossil eastern North American Agkistrodon and Crotalus. The results show that vertebrae of Agkistrodon and Crotalus can reliably be classified to genus and species using these methods. Based on the statistical analyses, four of the …


Assessing The Appropriateness Of Free-Roaming Cat Management Strategies Based On Resident Perspectives In A Small Pennsylvania Municipality, Brianna Marks May 2023

Assessing The Appropriateness Of Free-Roaming Cat Management Strategies Based On Resident Perspectives In A Small Pennsylvania Municipality, Brianna Marks

Electronic Theses and Dissertations

The popularity and mismanagement of free-roaming cats has resulted in invasive populations responsible for over-predation of birds and small mammals and increased disease transmission to humans and animals (Bies, 2014; Crowley et al., 2020). Management effectiveness fluctuates between communities due to varying opinions of free-roaming cats by governments and the public, which can influence management development and success (Deak et al., 2019). This research assesses the relationship between community perspectives of free-roaming cats and management. A survey of residents in a small Pennsylvania municipality was conducted with questions pertaining to free-roaming cats and management preferences in the community. Over 50% …


Detecting Native Freshwater Mussels In Pennsylvania Waterways: Comparison & Validation Of Environmental Dna Methods, Meredith Bennett May 2023

Detecting Native Freshwater Mussels In Pennsylvania Waterways: Comparison & Validation Of Environmental Dna Methods, Meredith Bennett

Electronic Theses and Dissertations

North America is home to approximately one third of the world's freshwater mussel species. They are highly imperiled organisms due to habitat destruction and invasive species. Traditional surveys rely on visual identification of mussels, but individuals tend to be rare and difficult to identify. An alternative method is to extract environmental DNA (eDNA) from water samples, which has advantages over traditional sampling, including less sampling effort and fewer hazards to researchers and organisms. We conducted a review of the two main eDNA approaches: single-species detection and metabarcoding. We also developed and validated metabarcoding primers for the detection of native mussels. …


Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano May 2023

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …


Understanding The Impacts Of Global Change: From Students To Microbes., Kylea Garces May 2023

Understanding The Impacts Of Global Change: From Students To Microbes., Kylea Garces

Electronic Theses and Dissertations

Global change is a crucial process, affecting every organism, from the billions of humans on earth, to the billions of microbes in the soil belowground. Evaluating the impacts of the many drastic changes associated with global change is essential in advancing our understanding in how to mitigate these consequences. Alongside the production of basic ecological knowledge associated with these environmental changes, improving education practices to promote science literacy surrounding global change is another step towards a more optimistic future. This dissertation investigates global change from two standpoints: ecologically, where increased atmospheric nitrogen (N) deposition alters plant-fungal endophyte symbiosis, and pedagogically, …


Neonate Atlantic Sharpnose Shark (Rhizoprionodon Terraenovae) Relative Abundance And Body Condition In Two South Carolina Estuaries Varying In Urbanization, Rileigh E. Hawk May 2023

Neonate Atlantic Sharpnose Shark (Rhizoprionodon Terraenovae) Relative Abundance And Body Condition In Two South Carolina Estuaries Varying In Urbanization, Rileigh E. Hawk

Electronic Theses and Dissertations

Urbanization near estuaries has been shown to affect the growth and survival of juvenile sharks using the system as a nursery. North Inlet and Murrells Inlet, South Carolina, are similarly-sized, tidally-dominated, bar-built estuaries with extensive Sporobolus-lined tidal creeks but differ in degree of human impact. Previously, Murrells Inlet was shown to have a lower abundance and diversity of large sharks than North Inlet and Atlantic Sharpnose Sharks (Rhizoprionodon terraenovae) were shown to use North Inlet as a primary nursery. To examine potential differences in neonate shark abundance and growth between a developed estuary, Murrells Inlet, and a protected estuary, North …


Vibroacoustic Response Of The Tympanic Membrane To Hyoid-Borne Sound Generated During Echolocation In Bats, Chelsie Snipes May 2023

Vibroacoustic Response Of The Tympanic Membrane To Hyoid-Borne Sound Generated During Echolocation In Bats, Chelsie Snipes

Electronic Theses and Dissertations

The hyoid apparatus in laryngeally echolocating bats forms a mechanical connection between the larynx and auditory bullae and has been hypothesized to transfer the outgoing echolocation call to the middle ear during echolocation call emission. We used µCT data to build models of the hyoid apparatus and middle ear from six species of bats and used finite element modeling (FEM) to measure the vibroacoustic response of the tympanic membrane due to hyoid-borne sound generated during echolocation. We found that hyoid-borne sound in all six species stimulated the eardrum within a range likely heard by bats. Although there were minor differences …


A Comparison Of Microsatellites And Single Nucleotide Polymorphisms For The Assessment Of Population Structure In The Amblyomma Maculatum Koch, 1844 Species Complex, Henrey A. Deese Jan 2023

A Comparison Of Microsatellites And Single Nucleotide Polymorphisms For The Assessment Of Population Structure In The Amblyomma Maculatum Koch, 1844 Species Complex, Henrey A. Deese

Electronic Theses and Dissertations

The Gulf Coast tick, Amblyomma maculatum Koch, 1844 is widespread throughout North and Central America and is the primary vector for the emerging pathogen Rickettsia parkeri. In the U.S., the population in the Southwest (A. maculatum morphotype III) is morphologically different from the population east of the Rocky Mountains (A. maculatum morphotype II). This research tests the hypothesis that A. maculatum morphotype II and morphotype III represent distinct species through the analysis and comparison of 6 microsatellite loci and suite of 135,221 Single nucleotide polymorphisms (SNPs) generated from ddRADseq. Population genetic analysis of both microsatellites and SNPs …


Neural And Behavioral Evolution In An Eavesdropper With A Rapidly Evolving Host, Aaron W. Wikle Jan 2023

Neural And Behavioral Evolution In An Eavesdropper With A Rapidly Evolving Host, Aaron W. Wikle

Electronic Theses and Dissertations

The diversification of animal communication systems is driven by many interacting factors. Unintended receivers play an important part in this process, yet little is known about their role in signal evolution. Flies of the genus Ormia are parasitoids of crickets and rely on acoustic cues to locate hosts. In Hawaii, selection imposed by Ormia ochracea has led to recent and rapid diversification in the songs of their host. Here, we compare neural and behavioral responses of Hawaiian flies to those of an ancestral population to understand the role of parasitoid sensory and behavioral variation in the evolution of host songs. …


Surviving The Serenade: How Conflicting Natural And Sexual Selection Drove Rapid Diversification Of Mating Signals In An Insect, James H. Gallagher Jan 2023

Surviving The Serenade: How Conflicting Natural And Sexual Selection Drove Rapid Diversification Of Mating Signals In An Insect, James H. Gallagher

Electronic Theses and Dissertations

Understanding how the early stages of sexual signal diversification proceed is of critical importance because the nature of these microevolutionary dynamics can directly shape species trajectories and macroevolutionary patterns. Unfortunately, studying signal diversification is challenging because signals involve complex interactions between behavioral, morphological, and physiological components, many of which can only be measured in real time. Here we had the opportunity to directly study this process with the recent increase in sexual signal variation in Hawaiian populations of the Pacific field cricket (Teleogryllus oceanicus). In Hawaii, male song attracts both female crickets and a deadly acoustically orienting parasitoid …


Plant Community Response To Control Of A Dominant Invader At Multiple Scales, Alexander R. B. Goetz Jan 2023

Plant Community Response To Control Of A Dominant Invader At Multiple Scales, Alexander R. B. Goetz

Electronic Theses and Dissertations

Control of invasive Tamarix spp. in riparian systems has long been a priority for management in western North America, but questions remain regarding the response of the broader plant community to different treatments. Here we summarize a series of approaches at different scales to quantify the effects of Tamarix control on characteristics of this ecosystem, including provisioning of wildlife habitat. In the first chapter we analyzed findings of the last 20 years using meta-analysis and found that although treatment has been successful in reducing Tamarix and promoting native vegetation to some extent, most literature reports very small effect sizes and …


The Evolutionary Causes And Consequences Of Mammalian Hybridization, Kelsie E. Hunnicutt Jan 2023

The Evolutionary Causes And Consequences Of Mammalian Hybridization, Kelsie E. Hunnicutt

Electronic Theses and Dissertations

The natural recombination of divergent genomes within hybrid offspring provides windows through which we can study evolutionary processes and the dynamics of speciation. In this work, I use a combination of comparative and population genomics on both laboratory crosses of divergent rodent lineages and a hybrid zone of cottontail rabbits in the wild to study the causes and consequences of hybridization in mammals. Hybrid sterility is a common reproductive barrier between species that tends to preferentially manifest in the heterogametic sex and frequently genetically maps to the sex chromosomes. Thus, the sex chromosomes appear to play a special role in …